A sheet fastener has been typically used for fastening overlaid edges of a covering material.
For instance, a seat surface, a back surface, a headrest, an armrest and the like of a vehicle seat are finished with a cushion material such as a synthetic resin foam (base material) and a sheet-like top cover (covering material) over a surface of the cushion material. The top cover is three-dimensionally sewn in advance in a manner to fit to an outer shape of the cushion material. The top cover is put over the cushion material through a partly remaining opening of the top cover and is finished by lastly closing the opening. With this arrangement, a seam line and the like are unlikely to be exposed, thereby ensuring an excellent appearance. The opening is lastly closed by fastening the overlaid edges of the top cover using a sheet fastener made of a continuous molding material, thereby enhancing the appearance.
Such a sheet fastener is applicable to, in addition to a seat of a vehicle such as an automobile and a train, a seat of an airplane and a ship, a seat used at school and office, a cushion of sports gears and furniture such as a sofa and a bed for residence and medical care.
Moreover, in addition to the top cover such as the seat and the cushion, the sheet fastener is also applicable for fastening sheet edges of a structural object such as a tent, fastening cover edges of a package during transportation, and the like.
As a specific arrangement of such a sheet fastener, arrangements described in Patent Literatures 1 and 2 are known.
A sheet fastener of Patent Literature 1 includes a first member and a second member, each of which is a continuous member made of a synthetic resin by extrusion molding. The second member includes a U-shape part in cross section. A sheet edge is fixed to an end of the U-shape part while a bead is provided at the other end thereof. The first member is formed to have a U-shape part similar to the second member in an inverse direction.
When edges of a pair of sheets are fastened with the above fastener, the second member is pulled to a position where the first member is covered with the sheet. While openings of the U-shape parts of the first member and the second member face each other, the bead of the second member is inserted into the first member, where tension of the sheet of each of the first member and the second member works so that the first and second members respectively go into the innermost parts of the mutually facing U-shape parts thereof, thereby maintaining mutual engagement.
The sheet fastener of Patent Literature 2 includes a first member and a second member to which a sheet edge is fixed. The second member is formed in a plate having bulging ends and a bendable intermediate. The sheet edge is fixed to a base end of the second member. The first member includes a U-shape part in cross section, into which an end of the second member can be inserted and engaged.
When edges of a pair of sheets are fastened with the above fastener, the edge of one of the sheets is initially fixed to a base end of the second member. Then, the second member is rotated and a tip end thereof is inserted into the first member, so that the first member and the second member are engaged. At this time, while the sheet edge is wound around the base end of the second member, the intermediate of the second member is bent, so that the U-shape part of the first member can be covered.